1. Technical Field
The present invention relates generally to an optical receiver for converting an input optical signal to an electrical signal for data recovery and a method thereof in an optical transmission system.
2. Related Art
A variety of protocols are available to an optical transmission system, such as protocols for fiber distributed data interface (FDDI), enterprise systems connectivity (ESCON), fiber channel, gigabit Ethernet, and asynchronous transfer mode (ATM). Various bit rates are used for the protocols, including 125 megabits per second (Mbps), 155 Mbps, 200 Mbps, 622 Mbps, 1062 Mbps, 1.25 gigabits per second (Gbps), and 2.5 Gbps.
Among the protocols and bit rates, an optical transmission system selects an appropriate protocol/bit rate. Since the bit rate of an optical signal is preset in the optical transmission system, an optical receiver in a relay or a terminal operates at the bit rate according to the selected protocol. The bit rate corresponds to a transmission rate. The bit rate can be expressed as a transmission rate of a number of bits per second (bps).
I have found that it would be desirable to improve optical receiver technology. Efforts have been made to improve optics-related technologies.
Exemplars of recent efforts in the art include U.S. Ser. No. 09/484,061 for METHOD AND APPARATUS FOR IDENTIFYING BIT RATE applied for by Yang, U.S. Pat. No. 5,181,134 for A Photonic Cross-Connect Switch issued to Fatehi et al., U.S. Pat. No. 4,888,791 for A Clock Decoder and Data Bit Transition Detector for Fiber Optic Work Station issued to Barndt, Sr., U.S. Pat. No. 5,510,919 for An Optical System for Transmitting a Multilevel Signal issued to Wedding, U.S. Pat. No. 5,144,469 for A Method for the Transmission of Data Between Two Stations by Means of Optical Waveguides issued to Brahms et al., U.S. Pat. No. 5,550,864 for A Bit Rate-Insensitive Mechanism for Transmitting Integrated Clock and Data Signals over Digital Communication Link issued to Toy et al., U.S. Pat. No. 4,524,462 for A System for Jointly Transmitting High-Frequency and Low-Frequency Digital Signals over a Fiber-Optical Carrier issued to Cottatelucci, U.S. Pat. No. 6,069,722 for A Transmitter for Optically Transmitting Analog Electric Signals, and Digital Transmission System issued to Schlag, U.S. Pat. No. 6,034,801 for A Transmitting Device, Transmitting Apparatus and Optical Transmission System for Optically Transmitting Analog Electrical Signals issued to Pfeiffer, and U.S. Pat. No. 4,475,212 for A Frequency-Independent, Self-Clocking Encoding Technique and Apparatus for Digital Communications issued to McLean et al.
While these recent efforts provide advantages, I note that they fail to adequately provide an improved bit-rate independent optical receiver and method thereof having enhanced efficiency.